This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
This disclosure relates to systems, apparatuses and methods of aligning and connecting mating elements of subsea equipment and to wellhead connectors or to other subsea equipment when being suspended by a riser, wire, or cable (or their equivalents) and lowered into position.
Referring to FIGS. 1 & 2, the final stage of landing a blowout preventer (“BOP”) stack assembly onto a wellhead can take several hours if the assembly is swinging on the riser in pendulum fashion, moving laterally and radially with respect to the wellhead. While prior art compensation systems on the deploying vessel provide the assembly a degree of vertical stability, the lateral and radial movements can cause significant delays in landing and connecting a BOP to a wellhead owing to the need to align the mating elements of the connector.
Similarly, landing and latching a lower marine riser package (“LMRP”) to the lower BOP stack after a disconnect can be delayed while the correct alignment between the two is being achieved.
Both of these situations represent non-productive time and, therefore, have financial implications beyond the cost of the landing and disconnect operations. Shortening the time taken to align the mating elements of BOPs and wellhead connectors represents an opportunity to reduce the costs associated with the operation. Therefore, a need exists for systems and methods that dampen and reduce the pendulum effect of a BOP swinging on a riser and allow for easier alignment and make-up of the connectors.